For many years, patients with medical symptoms, such as pain, itchiness, and soreness, have been asked by health practitioners to designate the locations of their symptoms on pictures of the human body represented as silhouettes, for example, on a piece of cardboard or paper. In one common application, the McGill pain questionnaire, patients express the location of their symptoms by marking with a pen or pencil on front and back views of the human body. In a variation on this method, the Brief Pain Inventory also asks patients to place an X on the body diagram to represent the most painful location.
A major drawback of paper-and-pencil approaches to representing the location and intensity of pain on body diagrams is that there is no intuitive way to simultaneously indicate symptom location along with a grade of symptom intensity. Patients may not have the skill required to color areas of the body to represent intensities accurately, for example, using color or patterns. Also, there is no standard set of visual symbols to represent different levels or grades of intensity. With symptoms like pain, these existing techniques also do not allow the patient to map the depth of the pain within the body. These methods also limit the ability to fine-tune or change ratings. These methods are further limited in that the data generated by the patient is not automatically entered into a computer in a manner that allows results to be manipulated, analyzed, or displayed on a monitor for viewing by the attending physician or other health care professional.
More recently, computer programs have been developed to allow the patient to mark locations of pain on a diagram of the human body displayed on a monitor. One existing computerized method uses predefined visual icons to represent different types and intensities of pain, which requires the user to first select an icon from a palette and then drag the icon to a location on the diagram. Another computerized method allows a user to select predefined areas on a diagram of the human body. Such existing methods limit the user's ability to define a region of pain, the intensity of the pain, and the depth of the pain in a simple and precise manner.